pwr::pwr.t.test(n = 100, sig.level = 0.05, power = 0.9, type = "two.sample", alternative = "two.sided")
Two-sample t test power calculation
n = 100
d = 0.4606604
sig.level = 0.05
power = 0.9
alternative = two.sided
NOTE: n is number in *each* group